[Paul]

Just prompted by this discussion: http://speakev.com/threads/how-much-would-you-pay-for-this-leaf.1290/

What matters most (technically) in terms of EVs, would it be miles on the motor, or charges on the battery, both, or something else?

Generally now you can get good second hand ICE vehicles with high mileage as long as well looked after and serviced, what about EVs, what is the motor life expectancy for a LEAF, Tesla etc?

Just wondering really.

 

[Paul_Moxhay]

IMO...

I have no idea what the motor life might be but I would expect the motor to last well beyond the life of any car (?).

Battery health is what matters most I suppose. That is how much power will it store at 100%? For example, mine is at about 90% (it varies from day to day... don't ask me why!) which I take to mean that it has about 90% of its new capacity. This of course equates to about a 10% reduction in range over a new Mk1. I think this feels about right.

A lot of things contributes to battery health... number of charges both rapid and not, temperature the battery has been used and stored at, number of charges to 100%, number of times it was drained to below 20%... etc.
This can been seen with the indicator on the dash but for a more accurate determination use LeafSpy or hook up to a Nissan diagnostic computer!

Either way... I think that there will need to be more generally accepted ways to determine battery health because ultimately that will determine the potential range of the car now and how long it will be before that range drops off.

 

[brian orr]

Just how analytical are people, when buying 2nd hand cars?
I bet its whether they like the colour, respect the dealer, getting a good trade-in, or are getting a good finance deal! Even if you have a battery diagnostic, who can say what represents a sensible number for battery capacity - against a certain level of price?
EVs have surely got to be a better bet because of the reduced number of moving cars. How many 2nd hand cars have issues with exhaust pipes, water pumps, radiators, alternators, cams fat and fuel injection! There are armies of men working in grubby workshops - exploiting the 2nd hand car owner who doesn't want to pay main dealer prices!
My advice is to get the best possible price from a main dealer, in your chosen brand - its his guarantee that its worth a fair chunk. The dealer's staff will know how to diagnose and fix the car - buy it from a car super-market, or auction, and you may be in for a sorry tale, when faults occur! Buyer beware as they say!
If you subsequently need to take that car to a main dealer - you may well be exploited. I bought my No1 car in Brussels, when I worked there - but insisted on a UK-spec. Very often when we book it in for a service - they spin a yarn about the car not being 'on the system' - spares may be a problem. Of course there has not been a problem - but it indicates that dealers are ready to exploit any car that is an anomaly!

 

[Paul]

Wonder how Parker's etc are sizing this all up too?

 

[plymjack]

I did some research on batteries prior to purchase and am also an expert on lead acids (from submarines) in both cases battery life is optimised by managed charging cycles. Basically running it from 90+% down to 25% then back up to 95%.
Indeed we used to do a controlled cycle of charges /discharge every 3 months to maintain this.

Off course in the real world this is difficult, and when buying 2nd hand hard to verify (Although I think BMW certainly would have the details in their Connected Drive system somewhere. The worst case would be if the battery had had a lot of short discharge/charge cycles (eg 95-down to 80% then recharged back to 95%). The is how they were generally used on subs but had we no choice, but the battery was well monitored and maintained.

So it would be hard to say and I guess you end up paying your money and taking your bet!

(PS I say 95% referring to car batteries both lithium and sealed lead acids these are never fully charged to allow for the car to have some regenerative capacity - older lead acids can be charged to 100% and indeed are to gas the plates for maintenance)